Anchor Papers ~ Biology ~ Item 5


	Item 5 Anchor Papers

A student reads an advertisement from a fertilizer company. The advertisement claims their fertilizer increases the growth of tomato plants by 25 percent. The student decides to perform an experiment to test this claim. She performs the following procedure.

Choose three similar-sized tomato plants.
Plant each tomato plant in a small pot.
Place all three small pots into one container and place on a window sill.
Add fertilizer mixed with water to Plants 1 and 2.
Add only water to Plant 3.
Record the heights of the three plants after four weeks.

The student's results are shown in the table below.

Analyze the student's experiment to determine if it supports the claims made in the fertilizer company's advertisement. In your response, be sure to include

a description of the data needed to support the company's claim
an explanation of the results of the student's experiment
an evaluation of the student's experiment
a description of any changes you would make to the experiment; explain your answer

Write your answer in your Answer Book.

Score Level 1 Anchor Paper
This response shows some understanding. Although no evaluation of the experiment is provided, specific data (20 cm; 23 cm; 25%) are used to describe the validity of the company’s claim. Support for the suggested improvement (keeping the plants in separate containers) is minimal, and the student gives no explanation for design improvement.
Score Level 1 Anchor Paper
This response shows some understanding. The student recommends testing more plants and using the same type of tomatoes for the redesign and supplies a brief explanation (because there are many different kinds of tomatoes). Information addressing the first two parts of the question is combined (only one plant was larger and not even by 25%). The supporting details are minimally effective.
Score Level 2 Anchor Paper
This response shows a basic understanding of the question. The student briefly describes the data needed in order to support the company’s claim (plant 1 reached the height of 23 centimeters, plants 2 and 3 reached 20 centimeters; data would have to have plants 1 and 2 grow 25% more than plant 3). The response includes a supported evaluation (experiment was not complete), identifies a few changes to the experimental procedure (more tomato plants; put them in the same place), and explains why these changes improve the experiment (to get more accurate results). Overall, the supporting details are adequate.
Score Level 2 Anchor Paper
This response shows a basic understanding of the question. The student briefly describes the data needed in order to support the company’s claim (the tomatoes in pots 1 & 2 would have to grow to 25 centimeters) and provides specific, supporting details (25 is 25% more than 20, which is the height of the plant that only got water). A brief evaluation of the student’s experiment (Mabye the distribution of fertilizer was not equal) is accompanied by a minimally effective description of a change to the experimental procedure (have more than 3 plants; the outcome could be more conclusive).
Score Level 3 Anchor Paper
This response demonstrates a good understanding of the question. The student describes the data needed in order to support the company’s claim (plants 1 and 2 would have to grow to 25 centimeters, which is 25 percent more than 20). Generally complete supporting details are used to show some synthesis of information, especially in describing proposed changes to the experimental procedure (test more than two plants against the control group; allow the plants a greater amount of time; fertilizer might not take effect right away; same temperature levels; equal sunlight). An evaluation of the student’s experiment is only implied (would be in the better interest). The use of additional scientific terminology would enhance the response.
Score Level 4 Anchor Paper
This response demonstrates a full and complete understanding. Pertinent and complete supporting details are used to explain why the data does not support the company’s claim (the other 2 treated plants would have to grow to 25 cm; the control group, plant 3, grew to 20 cm; plant 1 grew to 23 cm; plant 2 grew to 20 cm; neither experimental plant grew to 25 cm). The student elaborates on each part of the question. Synthesis of information is evident as the student analyzes the data (The fertilizer is unconstant; one treated plant grew 3 cm more than the control but the other treated plant was the same height as the control) and describes how the experimental procedure can be improved by controlling variables (same type of soil, same type of pot; same amount of fertilizer and water) and using multiple trials. The response is enhanced by the use of appropriate scientific terminology (control group; experimental plant; variables; trials).
Score Level 4 Anchor Paper
This response contains evidence of a full and complete understanding. A thorough analysis of the experimental results, including specific numerical values for the expected results, is provided. This supports the student’s conclusion that the experiment does not corroborate the company’s claim. (For the plants with fertilizer to be 25% taller, they would have needed to be 25 cm each, and neither plant is that tall.) Evaluation of the student’s experiment is brief (could have been better planned). A complete synthesis of information is evident as reasons for redesigning the experimental procedure are provided. (There should have been more plants involved in the test so that one chance genetic difference between plants; would not throw off the entire experiment.) The use of scientific terminology reveals insight into important scientific principles, such as genetic variation within a species and averaging test results from multiple trials.

Anchor Papers ~ Biology ~ Item 5

Choose three similar-sized tomato plants.
Plant each tomato plant in a small pot.
Place all three small pots into one container and place on a window sill.
Add fertilizer mixed with water to Plants 1 and 2.
Add only water to Plant 3.
Record the heights of the three plants after four weeks.

The student's results are shown in the table below.

Analyze the student's experiment to determine if it supports the claims made in the fertilizer company's advertisement. In your response, be sure to include

a description of the data needed to support the company's claim
an explanation of the results of the student's experiment
an evaluation of the student's experiment
a description of any changes you would make to the experiment; explain your answer

Write your answer in your Answer Book.

Score Level 1 Anchor Paper
This response shows some understanding. Although no evaluation of the experiment is provided, specific data (20 cm; 23 cm; 25%) are used to describe the validity of the company’s claim. Support for the suggested improvement (keeping the plants in separate containers) is minimal, and the student gives no explanation for design improvement.

Score Level 1 Anchor Paper
This response shows some understanding. The student recommends testing more plants and using the same type of tomatoes for the redesign and supplies a brief explanation (because there are many different kinds of tomatoes). Information addressing the first two parts of the question is combined (only one plant was larger and not even by 25%). The supporting details are minimally effective.

Score Level 2 Anchor Paper

This response shows a basic understanding of the question. The student briefly describes the data needed in order to support the company’s claim (plant 1 reached the height of 23 centimeters, plants 2 and 3 reached 20 centimeters; data would have to have plants 1 and 2 grow 25% more than plant 3). The response includes a supported evaluation (experiment was not complete), identifies a few changes to the experimental procedure (more tomato plants; put them in the same place), and explains why these changes improve the experiment (to get more accurate results). Overall, the supporting details are adequate.

Score Level 2 Anchor Paper

This response shows a basic understanding of the question. The student briefly describes the data needed in order to support the company’s claim (the tomatoes in pots 1 & 2 would have to grow to 25 centimeters) and provides specific, supporting details (25 is 25% more than 20, which is the height of the plant that only got water). A brief evaluation of the student’s experiment (Mabye the distribution of fertilizer was not equal) is accompanied by a minimally effective description of a change to the experimental procedure (have more than 3 plants; the outcome could be more conclusive).

Score Level 3 Anchor Paper

This response demonstrates a good understanding of the question. The student describes the data needed in order to support the company’s claim (plants 1 and 2 would have to grow to 25 centimeters, which is 25 percent more than 20). Generally complete supporting details are used to show some synthesis of information, especially in describing proposed changes to the experimental procedure (test more than two plants against the control group; allow the plants a greater amount of time; fertilizer might not take effect right away; same temperature levels; equal sunlight). An evaluation of the student’s experiment is only implied (would be in the better interest). The use of additional scientific terminology would enhance the response.

Score Level 4 Anchor Paper

This response demonstrates a full and complete understanding. Pertinent and complete supporting details are used to explain why the data does not support the company’s claim (the other 2 treated plants would have to grow to 25 cm; the control group, plant 3, grew to 20 cm; plant 1 grew to 23 cm; plant 2 grew to 20 cm; neither experimental plant grew to 25 cm). The student elaborates on each part of the question. Synthesis of information is evident as the student analyzes the data (The fertilizer is unconstant; one treated plant grew 3 cm more than the control but the other treated plant was the same height as the control) and describes how the experimental procedure can be improved by controlling variables (same type of soil, same type of pot; same amount of fertilizer and water) and using multiple trials. The response is enhanced by the use of appropriate scientific terminology (control group; experimental plant; variables; trials).

Score Level 4 Anchor Paper

This response contains evidence of a full and complete understanding. A thorough analysis of the experimental results, including specific numerical values for the expected results, is provided. This supports the student’s conclusion that the experiment does not corroborate the company’s claim. (For the plants with fertilizer to be 25% taller, they would have needed to be 25 cm each, and neither plant is that tall.) Evaluation of the student’s experiment is brief (could have been better planned). A complete synthesis of information is evident as reasons for redesigning the experimental procedure are provided. (There should have been more plants involved in the test so that one chance genetic difference between plants; would not throw off the entire experiment.) The use of scientific terminology reveals insight into important scientific principles, such as genetic variation within a species and averaging test results from multiple trials.